1. Field of the Invention
The present invention relates to an optical multi-layer structure, and in particular relates to an optical multi-layer structure having improved surface hardness and a flat panel display (FPD) having the optical multi-layer structure.
2. Description of the Related Art
Due to being thin and light weight, and having low power consumption, flat panel display devices such as liquid crystal display devices have solved problems found in cathode ray tube (CRT) display technologies and are widely used in electronic devices, for example laptops, personal digital assistants (PDA), electronic books, projectors, and mobile phones.
In the current market, flat panel display devices are typically two-dimensional (2D) flat panel display devices. With the development of new display technologies, three-dimensional (3D) flat panel display devices have also emerged. Referring to FIG. 1, a cross section of a conventional flat panel display 10 is illustrated. The flat panel display 10 comprises a backlight module 12 and a display structure 16 disposed above the backlight module 12. The display structure 16 may be a liquid display structure or an organic light-emitting display structure. Further, the display structure 16 typically has polarizing films 14 and 18 adhered to its back side and front side, respectively, to convert a light 12a from the backlight module 12 into a linear polarized light. When applying the flat panel display 10 in a stereoscopic or three-dimensional display, a user viewing the display has to wear a viewing device (for example, shutter glasses) to make sure that the user's right eye and left eye can perceive correct images, respectively. Further, an optical film 20 is additionally adhered onto the polarizing film 18 on the front side of the display structure 16 to convert the linear polarized light into a circular polarized light. However, the optical film 20 does not have sufficient surface hardness (i.e. having a pencil hardness lower than 1 H), and as a result, the polarizing film of the three-dimensional flat panel display devices does not satisfy surface hardness requirements (i.e. the pencil hardness being equal to or greater than 3 H).
Thus, an optical multi-layer structure for flat panel display devices that improves or solves the problems described above is needed.